Notes on pulling EEC-IV codes | Page 3 | Ford Explorer - Ford Ranger Forums - Serious Explorations

  • Register Today It's free! This box and some ads will disappear once registered!

Notes on pulling EEC-IV codes

MrShorty

Explorer Addict
Joined
December 27, 2001
Messages
5,078
Reaction score
16
City, State
Spanish Fork, UT
Year, Model & Trim Level
92 XLT and '87 Bronco II
I'm sorry, but my diagrams (mostly from the internet) don't identify which pin is #4 at the self-test connector. I'm not even sure if Vref is represented at the self-test connector.
 
<

Join the Elite Explorers $20 Gets rid of the ads!

Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private conversations, and more. Join Today. Your support is greatly appreciated.




KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
I'll try and get my scanner to work and post the photo copies up here. But until then, if you are looking at the front side of the self test plug they are numbered left to right and top to bottom.

(The top two pins)
left pin is #1 the right is #2
(bottom four pins)
Far left is three, center left is four, center right is five (not used), far right is six

If that makes sence
 
<



<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
Think I've got a handle on the problem I'm having. Seems that the #4 pin is not getting sufficient power, I threw a test light on that pin with the gator clip on the Pos battery side and there was a dim glow until I turned the key then I started getting cel flashes like normal so I hooked my code reader up per the manual while still having the test light hooked up and I got 111 which is pass on all koeo tests. I'm sure I've cleared any codes but now but at least I can do the koer tests tomorrow. I'll post my findings then

Edit: just pulled codes again, and everything checked out ok, but I had to apply power directly from the battery to the number four pin so im still having problems with the light not coming on when the ignition is turn to the ON position.
 
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
did some diag... checked the voltage at pin 17 on the pcm (to CEL tan/red) and its only showing .065v when the key is switched on. then slowly drops to about .010v

ohms is 00.3 from pin 17 to the gauges (tan/red)

i have no idea where to go from here and i cant get it smogged without the light working correctly... could really use some help guys.
 
<



MrShorty

Explorer Addict
Joined
December 27, 2001
Messages
5,078
Reaction score
16
City, State
Spanish Fork, UT
Year, Model & Trim Level
92 XLT and '87 Bronco II
According to your scans, pin 17 is STO. I don't see the CEL/MIL on either of our wiring diagrams, but, if it is like other elements in the engine management system, it will be ground side switched at pin 17 (as the CEL seems to be tied into the STO circut). So, assuming your are measuring voltage at pin 17 relative to ground, and because the CEL should be on KOEO, no voltage at pin 17 seems normal (unless my "ground side switch" assumption is wrong).

At this point I think we need a wiring diagram that shows how the CEL is supposed to be wired in. If it is, as I suspect, ground side switched, then we need to verify power to the CEL.
 
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
From what the tech at my work say, the PCM does not supply power to anything. It only grounds circuits. Which means that it should be getting power from somewhere within the circuit but I cant see where the circuit would be getting power from.

The diagrams I have are from the ford dealer I work for, I'm a detailer there but I finally got promoted into the the apprenticeship :bounce::bounce::bounce::bounce: program to become a tech.
 
<



MrShorty

Explorer Addict
Joined
December 27, 2001
Messages
5,078
Reaction score
16
City, State
Spanish Fork, UT
Year, Model & Trim Level
92 XLT and '87 Bronco II
From what the tech at my work say, the PCM does not supply power to anything. It only grounds circuits.
He's mostly correct.

Which means that it should be getting power from somewhere within the circuit but I cant see where the circuit would be getting power from.
If you look at your EEC wiring 3 diagram, it shows a leg coming off of the self-test connector going to the instrument cluster (I suspect the MIL specifically) and then refers to p 62-2. That's where power will be getting to pin 17, through the MIL. If it is like the other engine management circuits, I expect the MIL gets power from the EEC relay like the rest of the engine management system. Since the PCM appears to have power, I suspect that means a break between the EEC relay and the MIL.
 
<



Tbars4

Moderator Emeritus
Elite In Memoriam
Joined
March 4, 2007
Messages
26,470
Reaction score
70
City, State
anaheim hills,california
Year, Model & Trim Level
95 ranger 4x4/ 91 X 4x4
..I had a similar "No CEL" on my 91 and it turned out the EEC relay under the relay box in engine bay was not not making good contact as it had some corrosion on the prongs..The "No CEL" was the only problem I had related to that relay and when I fixed it I was able to paperclip read my error code..:dunno:

..Pulled the relay, cleaned up the prongs and all was well..I did however change that relay asap fearing it may have gotten weak and didn't need any future problems..
 
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
MIL? Not sure what that means.


I cleaned up all the prongs on the relays so well they have a good reflection. Still no change.
 
<



BrooklynBay

Moderator & long time member.
Staff member
Moderator
Elite Explorer
Joined
November 11, 2005
Messages
55,226
Reaction score
714
City, State
Brooklyn, NY
Year, Model & Trim Level
88 89 93 95 96 Aerostars
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
I just didn't know what MIL stood for. Thanks.

Wish I had the list of ground wire locations today. But I'll have to look them up when I get to work tomorrow.
 
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
..I had a similar "No CEL" on my 91 and it turned out the EEC relay under the relay box in engine bay was not not making good contact as it had some corrosion on the prongs..The "No CEL" was the only problem I had related to that relay and when I fixed it I was able to paperclip read my error code..:dunno:

..Pulled the relay, cleaned up the prongs and all was well..I did however change that relay asap fearing it may have gotten weak and didn't need any future problems..

I wonder if the female side of the plugs are corroded. They weren't to bad but you never know. I also went through the under good max fuses and cleaned those up too.
 
<



MrShorty

Explorer Addict
Joined
December 27, 2001
Messages
5,078
Reaction score
16
City, State
Spanish Fork, UT
Year, Model & Trim Level
92 XLT and '87 Bronco II
IIRC, 2 of the 3 PCM grounds go straight to the "pigtail" on the negative battery cable. The 3rd ground might go to the body near the PCM.
 
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
I was thinking the same thing about the 3rd one. There's a ground wire right next to it. Haven't had a chance to check it out the underside of the eyelet but the topside looked good
 
<



KJL

Well-Known Member
Joined
August 1, 2012
Messages
157
Reaction score
0
City, State
TURLOCK, CA
Year, Model & Trim Level
92 4.0 4x4. 00 4.0 2x4
fyi guys (since i know a lot of threads get dropped dead with no update on the solution)

my problem was just a bad ground. there is one ground on the drivers side fender well in the engine bay just rear of the rad/washer bottle for the pcm and one right next to the pcm they are both bolted to the sheet metal.

edit: now she runs perfect
 
<



Exploring XLT

Never Stop Explorering
Elite Explorer
Joined
August 12, 2016
Messages
284
Reaction score
108
Location
Stony Plain, Alberta, Canada
City, State
Stony Plain
Year, Model & Trim Level
93 Ford Explorer XLT 4WD
Hey thanks for the write up,
engine runs rough and occasionally gives check engine light. Fuel economy is down as well, and the amount of power that the engine gives will vary without changing throttle position.
KOEO
111 pass code
CM
176 System indicates lean (bank 2)
189 Fuel system at rich adaptive limit
KOER
136 System indicates lean (bank 1)
Any help is appreciated
 
<



BrooklynBay

Moderator & long time member.
Staff member
Moderator
Elite Explorer
Joined
November 11, 2005
Messages
55,226
Reaction score
714
City, State
Brooklyn, NY
Year, Model & Trim Level
88 89 93 95 96 Aerostars
<



<

Join the Elite Explorers $20 Gets rid of the ads!

Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private conversations, and more. Join Today. Your support is greatly appreciated.




BrooklynBay

Moderator & long time member.
Staff member
Moderator
Elite Explorer
Joined
November 11, 2005
Messages
55,226
Reaction score
714
City, State
Brooklyn, NY
Year, Model & Trim Level
88 89 93 95 96 Aerostars
<



Top